The immunome of soy bean allergy: Comprehensive identification and characterization of epitopes.

BACKGROUND: The precise mapping of multiple antibody epitopes recognized by patients' sera allows a more detailed and differentiated understanding of immunological diseases. It may lead to the development of novel therapies and diagnostic tools.

OBJECTIVE: Mapping soy bean specific epitopes relevant for soy bean allergy patients and persons sensitized to soy bean, and analysis of their IgE/IgG binding spectrum.

METHODS: Identification of epitopes using sera, applying an optimized peptide phage display library followed by next-generation sequencing, specially designed in silico data analysis and subsequent peptide microarray analysis.

RESULTS: We were able to identify more than 400 potential epitope motifs in soy bean proteins. More than 60% of them have not yet been described as potential epitopes. Eighty-three peptides, representing the 42 most frequently found epitope candidates, were validated by microarray analysis using 50 sera from people who have been tested positive in skin prick test (SPT). Of these peptides, 56 were bound by antibodies, 55 by serum IgE, 43 by serum IgG and 30 by both. Person-specific epitope patterns were found for each individual and protein.

CONCLUSIONS: For individuals with clinical symptoms, epitope resolved analyses reveal a high prevalence of IgE binding to a few soy bean specific epitopes. Evaluation of individual immune profiles of patients with soy bean sensitization allows the identification of peptides that do facilitate studying individual IgE/IgG epitope binding patterns. This enables discrimination of sensitization from disease, such assay test has the potential to replace SPT assays.